Pre press processing technology of flexo printing
when using the traditional plate making method, 1% of the points are unstable in the production process and are very easy to lose, so the minimum point formed on the printing plate is 2%, and the 2% point will increase to 10% after printing, so the minimum point on the printing sample is 10%, and the points below 10% cannot be printed. At this time, the following methods can be used to skillfully avoid and solve
(1) ignore some levels without affecting the printing effect, even if it is less than 2%
● the mainstay of high-strength steel automotive materials (2) change all highlights below 2% to 2%. Because the human eye's perception of color is relative, in some cases, it will produce an illusion that 2% of the points are regarded as highlights
(3) replace a certain color with other colors, for example, black is often used to replace blue in food packaging, black is used to replace red in leaf printing, or light color with the same hue is used to replace dark color, etc. the methods vary
the above methods actually lost less than 10% points in printing. With the progress of technology, Esko graphics has developed a new point technology to avoid the combination of FM and am points due to impurities such as water, which has alleviated the problem. Using frequency modulation points in the highlight area of the image (1% - 3% points) just solves the problem that 1% points on the flexo can't be saved. In addition, many companies have introduced new computer direct plate making equipment, which can produce 1% points and print less than 10% points through different exposure methods, but the printing plate has low printing resistance, and the printing factory changes the printing plate more times. In short, because there are too many and changeable interference factors in the printing environment, the staff should comprehensively consider various factors during prepress processing, so that the flexo can meet the printing requirements to the greatest extent, and finally get the ideal print
flexographic printing has its own characteristics and advantages. Flexographic printing uses water-based ink or alcohol based ink with environmental protection characteristics, which is not harmful to human body, especially suitable for food. Most of the packaging of pharmaceutical products and liquid milk are printed by flexographic printing. Secondly, the narrow width flexographic printing machine can add printing units to complete die cutting, embossing, ironing, promote the harmonious development of the new material industry, dislocation development printing and other processes, improve production efficiency and reduce production costs. Thirdly, now customers have strict requirements for the consistency of external packaging colors (especially field colors). Flexographic printing can almost be the same as the first printing, ensuring the stability of packaging
therefore, flexographic printing is gradually recognized by customers, and hundreds of flexographic printing production lines have been introduced in China in just a few years; At the same time, the application of flexographic printing has driven the development of flexographic plate making industry. However, domestic flexo plate making started late for many reasons. One of the main reasons is that flexo pre press processing is difficult and difficult, but it has achieved stability. If the prepress treatment of flexo is carried out according to the method of offset printing or gravure plate making, there will be many problems in the printed samples, such as darker color, loss of layers, missing points or hard edges in the highlights, etc
LINK
Copyright © 2011 JIN SHI